A polyester recycling byproduct high-value processing feeding control method and system

Abstract

The application relates to the technical field of high-value treatment of polyester recovery by-products, in particular to a feeding control method and system for high-value treatment of polyester recovery by-products, wherein the method sets ideal feeding ratios and feeding speeds, combines real-time gas pressure fluctuation in a pyrolysis furnace, dynamically adjusts the feeding speed of a feeding machine, and ensures the stability and efficiency of gas production. The specific steps include: setting initial parameters according to the gas production ratio of alcohol by-products and ester by-products, monitoring the gas pressure fluctuation in the pyrolysis furnace and calculating the actual gas production, comparing the actual gas production with the theoretical gas production, and adjusting the feeding speed according to the deviation. In addition, the change of liquid production and solid production is also considered to further optimize the feeding control strategy. The application adjusts the gas production efficiency by controlling the feeding speed of the feeding machine for different raw materials, so that the gas production efficiency is relatively constant.

Description

Technical Field

[0001] This application relates to the technical field of PET polyester by-product treatment, and in particular to a feeding control method and system for high-value treatment of recycled polyester by-products. Background Technology

[0002] PET (Polyester Petroleum) is an important plastic widely used in textiles, packaging, and other fields. However, PET has a long natural degradation cycle, which easily causes environmental pollution. To address this issue, various methods for recycling PET polyester materials are currently available, such as physical, biological, and chemical methods. Chemical methods primarily involve alcoholysis, where waste PET is alcoholyzed to produce reactants for polyester, which are then reused in the production of PET polyester. However, alcoholysis still generates a certain amount of waste that cannot be recycled, commonly known as byproducts (including alcohol and ester byproducts). If these byproducts are not properly treated, they will still cause environmental pollution.

[0003] The applicant proposed a method for treating alcohol and ester byproducts using pyrolysis. The production line mainly consists of a feeding and preheating module, a heating device, a continuous pyrolysis furnace, a liquid separation and cooling module, a gas purification and conveying module, and a discharge module. The feeding and preheating module includes a feeder, a buffer tank, a feeding sealing device, and a preheating assembly. Raw materials in the buffer tank are fed into the preheating assembly through the feeding sealing device. After preheating by the preheating assembly, the raw materials are continuously fed into the continuous pyrolysis furnace by the feeder. During the pyrolysis process, pyrolysis gaseous products and solid products (carbon black) are generated. The pyrolysis gaseous products condense into combustible non-condensable gases and liquid condensable liquids. The main component of the non-condensable combustible gas is small molecule alkanes, which can be reused as fuel and used as a heating energy source for the continuous pyrolysis furnace, heating device, and preheating module.

[0004] However, the thermal decomposition gas production rates of alcohol and ester byproducts differ significantly, which affects subsequent processes such as fuel recovery and reheating, and gas-liquid separation. Therefore, it is necessary to adjust the feeding rates of both ester and alcohol byproducts to achieve a more constant gas production rate. Summary of the Invention

[0005] One of the objectives of this application is to provide a feeding control method for the high-value treatment of polyester recycling by-products. By controlling the feeding speed of the feeder for different raw materials (ester by-products, alcohol by-products, or a combination of both), the gas production efficiency can be adjusted to make the product efficiency relatively constant.

[0006] One of the above-mentioned objectives of this invention is achieved through the following technical solution: A method for controlling the feeding of recycled polyester by-products for high-value treatment, the method comprising: The ideal feeding ratio and ideal feeding speed of the feeder are set based on the gas production ratio of alcohol by-products and ester by-products, and the theoretical gas production m per unit time t is obtained. gll ; The real-time gas pressure fluctuations inside the pyrolysis furnace are obtained, and the current gas production m within a unit time t is obtained during the gas pressure fluctuations. gdq ; Compare the theoretical gas production m gll Compared with the current gas production m gdq The amount of alcohol and ester byproducts is determined to be excessive or insufficient, and the feeding speed of the feeder is adjusted accordingly. Preferably, the real-time gas pressure fluctuation in the pyrolysis furnace is obtained, and the current gas production m per unit time t is obtained during the gas pressure fluctuation. gdq include: Under stable gas production, the real-time gas pressure fluctuation in the pyrolysis furnace is obtained, and the current gas pressure Pdq and current temperature Tdq are obtained when the gas pressure fluctuates. Obtain the gas flow rate Vgt at the pyrolysis gas outlet, and calculate the total gas production volume Va per unit time t based on the gas flow rate Vgt at the pyrolysis gas outlet, i.e. Va = Vgt·t. Calculate the current gas production volume m based on the relationship between the gas production volume Va and the current gas pressure Pdq. gdq .

[0007] Preferably, the calculation of the current gas production volume m based on the relationship between the gas production volume Va and the current gas pressure Pdq is... gdq The calculation formula is as follows: Based on PV=nRT and n=m / M, we can obtain... m gdq =Pdq·VM / RT=Pdq·(10^-3)Va·M / R(Tdq+273.15); In the formula, P is pressure, V is gas volume in L, R is ideal gas constant, T is temperature in K, and M is gas molar coefficient. Preferably, the comparison of the theoretical gas production m gll Compared with the current gas production m gdq ,like: m gll -α≤m gdq ≤m gll If +α, then there is no need to adjust the feeding speed, where α is the gas production error; m gll -α>m gdq If the feeding speed is increased, then α is the gas production error. m gll +α<m gdq If the feeding speed is reduced, then the gas production rate is decreased, where α is the gas production error. Preferably, when the m gll -α>mgdq or the m gll +α<m gdq hour: Obtain the theoretical liquid production rate m per unit time t yll and theoretical solid production m sll And to obtain the current liquid production volume m within a unit time t during the pressure fluctuation. ydq and current solid production m sdq ; Compare the theoretical liquid production rate m yll Compared with the current liquid production rate m ydq、 The theoretical solids yield m sll Compared with the current solid production m sdq ; Calculate the theoretical gas production m gll Compared with the current gas production m gdq Gas production difference m gc Based on the ideal feeding ratio and stable gas production rate of the feeder, the gas production difference m within a unit time t is calculated. gcz The required feed amount needs to be adjusted accordingly. Preferably, the ideal feed ratio is 8:2 for alcohol by-products and 2 for ester by-products. Preferably, the stable gas production rate of the alcohol by-products is 27%, the stable liquid production rate is 63%, and no solids are produced; the stable gas production rate of the ester by-products is 90%, the stable solid production rate is 10%, and no liquids are produced. Preferably, when m... gll +α<m gdq hour: If m ydq >m yll m sdq >m sll This reduces the amount of alcohol and ester byproducts fed into the feeder, thereby reducing the feeding speed of the feeder for alcohol and ester byproducts. If m ydq >m yll m sdq ≤m sll This reduces the amount of alcohol by-products fed into the machine, thereby reducing the feeding speed of the alcohol by-product feeder. If m ydq ≤m yll m sdq ≤m sll This reduces the amount of alcohol and ester byproducts fed into the machine, thereby reducing the feeding speed of the alcohol and ester byproduct feeder. m ydq ≤m yll m sdq >m sllThis reduces the amount of ester by-products fed into the machine, thereby reducing the feeding speed of the ester by-product feeder.

[0008] Preferably, when the m gll -α>m gdq hour: If m ydq <m yll m sdq ≥m sll This increases the amount of alcohol by-products fed into the machine, thereby increasing the feeding speed of the alcohol by-product feeder. If m ydq <m yll m sll <m sdq This increases the amount of alcohol and ester by-products fed into the machine, thereby increasing the feeding speed of the alcohol and ester by-product feeder. If m ydq ≥m yll m sdq ≥m sll This increases the amount of alcohol and ester by-products fed into the machine, thereby increasing the feeding speed of the alcohol and ester by-product feeder. If m ydq ≥m yll m sdq <m sll This increases the amount of ester by-products fed, thereby increasing the feeding speed of the ester by-product feeder.

[0009] In summary, this application dynamically adjusts the feeding speed of the feeder by real-time monitoring of gas pressure fluctuations and gas production within the pyrolysis furnace. Furthermore, by controlling the feeding of different raw materials (ester byproducts, alcohol byproducts, or a combination of both), the gas production efficiency is adjusted to maintain a relatively constant level. This not only improves resource utilization and reduces waste but also prevents subsequent processes such as fuel recovery and reheating, and gas-liquid separation from being affected by unstable gas production efficiency. Simultaneously, precise control of the feeding speed ensures stable gas pressure and temperature within the pyrolysis furnace, enhancing the safety and reliability of the entire production process.

[0010] The second objective of this application is to provide a feeding control system for the high-value treatment of polyester recycling by-products. The purpose is to solve the problem that the gas production efficiency of different raw materials (ester by-products, alcohol by-products or a combination of both) varies during the pyrolysis process, which affects subsequent processes such as fuel recovery and reheating, and gas-liquid separation.

[0011] The second objective of this invention is achieved through the following technical solution: A feeding control system for high-value treatment of polyester recycling by-products, used to execute the above method, the system comprising: Initialization module: Used to set the ideal feeding ratio and ideal feeding speed of the feeder based on the gas production ratio of alcohol and ester byproducts, and to obtain the theoretical gas production m per unit time t. gll ; Gas pressure and volume acquisition module: used to acquire real-time gas pressure fluctuations within the pyrolysis furnace, and to acquire the current gas production volume m per unit time t during the gas pressure fluctuations. gdq ; Speed ​​regulation feedback module: used to compare the theoretical gas production m gll Compared with the current gas production m gdq To determine whether there is too much or too little alcohol or ester byproduct, the feeding speed of the feeder can be adjusted.

[0012] In summary, this application uses a gas pressure and volume acquisition module to monitor gas pressure fluctuations and gas production in the pyrolysis furnace in real time. Based on the fluctuations, it calculates and feeds back the gas production difference, accurately calculating whether there is too much or too little raw material. This allows for dynamic adjustment of the feeding speed of the feeder. By controlling the feeding of different raw materials (ester byproducts, alcohol byproducts, or a combination of both), the gas production efficiency is adjusted to maintain a relatively constant efficiency. This not only improves resource utilization and reduces waste but also prevents unstable gas production efficiency from affecting subsequent processes such as fuel recovery and reheating, and gas-liquid separation. Furthermore, precise control of the feeding speed ensures stable gas pressure and temperature within the pyrolysis furnace, improving the safety and reliability of the entire production process. Attached Figure Description

[0013] Figure 1 This is an overall flowchart of the feeding control method in Embodiment 1 of this application; Figure 2 This is a flowchart of step S2 in Embodiment 1 of this application; Detailed Implementation The following will be combined with the appendix Figure 1-2 The technical solutions in the embodiments of the present invention are clearly and completely described herein. The described embodiments are only possible technical implementations of the present invention and not all possible implementations. Those skilled in the art can obtain other embodiments in conjunction with the embodiments of the present invention without creative effort, and these embodiments are also within the protection scope of the present invention.

[0014] The inventors of this application have discovered that PET polyester is an important plastic with wide applications in textiles, packaging, and other fields. However, PET has a long natural degradation cycle, which easily causes environmental pollution. To address this issue, various methods exist for recycling PET polyester materials, such as recycling and reprocessing it into PET polyester for reuse, or using chemical methods to degrade PET and obtain raw materials for PET production. However, these methods generate a certain amount of waste that cannot be further recycled, commonly known as byproducts (alcohol byproducts and ester byproducts). If these byproducts are not further treated, they will still cause environmental pollution. Therefore, this application mainly adopts the following method to set the ideal feeding ratio and ideal feeding speed of the feeder based on the gas production ratio of alcohol and ester byproducts, and obtains the theoretical gas production m per unit time t. gll The unit time t can be determined by the pyrolysis time of the by-products in the pyrolysis furnace, or it can be determined according to actual needs. This application dynamically adjusts the feeding speed of the feeder by real-time monitoring of gas pressure fluctuations and gas production in the pyrolysis furnace, ensuring the stability of gas production efficiency, improving resource utilization, reducing resource waste, and avoiding the impact on subsequent processes such as fuel recovery and reheating, and gas-liquid separation due to unstable gas production efficiency. The following is a further detailed description of this application.

[0015] Example 1: Reference Figure 1-2 The feeding control method for high-value treatment of polyester recycling by-products provided in this application includes the following steps: S1. Based on the gas production ratio of alcohol byproducts and ester byproducts, set the ideal feeding ratio and ideal feeding speed of the feeder, and obtain the theoretical gas production m per unit time t. gll , where the unit time t is determined by the pyrolysis time of the by-products in the pyrolysis furnace.

[0016] Specifically, the gas production ratios of alcohol byproducts and ester byproducts are 27% and 90%, respectively, with an ideal feed ratio of alcohol byproducts:ester byproducts = 8:2. This means that for every 8 parts of alcohol byproducts fed in, 2 parts of ester byproducts are fed in. The ideal feeding rate can be adjusted according to the actual needs of the production line. For example, there are two sets of feeders, A and B, responsible for feeding alcohol byproducts and ester byproducts, respectively. Assuming that the maximum feeding capacity of each set of feeders is 100 kg per hour, the ideal feeding rate is 100 kg of mixed byproducts per hour, and the pyrolysis time of the byproducts in the pyrolysis furnace is 1 hour, i.e., unit time t = 1 hour. Of course, the pyrolysis time of the byproducts in the pyrolysis furnace can be adjusted according to the actual situation, such as 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc. Therefore, the feeding ratio of feeders A and B remains 8:2, i.e., 80 kg and 20 kg per hour, respectively. Theoretical gas production mgll Based on experimental or historical data, assuming an input of 100 kg of mixed byproducts per hour, the theoretical gas production is 27%×80+90%×20=21.6+18=39.6 kg.

[0017] S2. Obtain the real-time gas pressure fluctuation in the pyrolysis furnace, and obtain the current gas production m per unit time t when the gas pressure fluctuates. gdq .

[0018] Specifically, pressure fluctuations within the pyrolysis furnace can be monitored in real time using pressure sensors. When the pressure fluctuation exceeds a set threshold, [further action is taken]. Figure 1-2 Perform the following steps.

[0019] S21. Obtain the current gas pressure Pdq and current temperature Tdq when the gas pressure fluctuates. The method for judging the gas pressure fluctuation is as follows: when the theoretical gas pressure in the pyrolysis furnace is Pll = Pdq ± β, where β is the gas pressure error coefficient, if Pll > Pdq + β, it indicates that the gas pressure in the pyrolysis furnace is insufficient, and the gas production decreases; if Pll < Pdq - β, it indicates that the gas pressure in the pyrolysis furnace is too high, and the gas production increases. For example, assuming the standard working gas pressure in the pyrolysis furnace is Pll = 100KPdq, and the gas pressure error coefficient β is set to 5KPdq. If Pll > Pdq + β, i.e., Pdq < 95KPdq, it is determined that the gas pressure in the pyrolysis furnace is insufficient, and the gas production decreases. If Pll < Pdq - β, i.e., Pdq > 105KPdq, it is determined that the gas pressure in the pyrolysis furnace is too high, and the gas production increases.

[0020] S22. Under stable gas production, obtain the gas flux Vgt at the pyrolysis gas outlet. Calculate the total gas production volume Va per unit time t based on the gas flux Vgt at the pyrolysis gas outlet, i.e., Va = Vgt·t.

[0021] The gas flow rate Vgt at the pyrolysis gas outlet can be measured using a flow meter. The total gas production volume Va per unit time t can be calculated based on the gas flow rate Vgt, i.e., Va = Vgt·t. For example, if the gas flow rate Vgt at the pyrolysis gas outlet is 100 m^3 / h, then the total gas production volume Va per unit time t is 100 m^3.

[0022] S23. Calculate the current gas production volume m based on the relationship between the gas production volume Va and the current gas pressure Pdq. gdq .

[0023] Specifically, the current gas production m gdq It can be calculated based on the ideal gas law PV=nRT and n=m / M, where P is the pressure in Pa, V is the gas volume in m^3, R is the ideal gas constant, T is the temperature in K, and M is the gas molar coefficient.

[0024] In this embodiment, since the temperature unit is Celsius, it is necessary to convert Celsius to Kelvin. Therefore, the conversion calculation formula is as follows: m gdq =Pdq·VM / RT=Pdq·Va·M / R(Tdq+273.15); In the formula, Tdq is the current pyrolysis temperature of the pyrolysis furnace, in °C.

[0025] In this embodiment, since the pyrolysis gas produced after pyrolysis is a combustible gas and its component is methane, the ideal gas constant R = 8.314 J / (mol·K) and the gas molar coefficient M = 16 g / mol.

[0026] For example: Assume the current gas pressure Pdq = 90 kPa = 90000 Pa, the total gas production volume Va = 100 m³ per unit time t, the pyrolysis temperature Tdq = 300℃, M = 16 g / mol, and R = 8.314 J / (mol·K), then the current gas production m gdq = (90000·100·16) / (8.314·(300+273.15))≈30.22kg.

[0027] S3, Comparison of theoretical gas production m gll Compared with the current gas production m gdq To determine whether there is too much or too little alcohol or ester byproduct, the feeding speed of the feeder can be adjusted.

[0028] Specifically, compare the theoretical gas production m gll Compared with the current gas production m gdq ,like: m gll -α≤m gdq ≤m gll If +α, then there is no need to adjust the feeding speed; m gll -α>m gdq This increases the feeding speed; m gll +α <m gdq If so, the feeding speed will be reduced.

[0029] In the above, α represents the gas production error.

[0030] For example, assuming α is 1 kg, when m gdq When the mass is less than 38.6 kg, increase the feeding speed; when m gdq When the weight exceeds 40.6 kg, reduce the feeding speed.

[0031] Specifically, when m gll -α>m gdq or m gll +α<mgdq hour: Obtain the theoretical liquid production rate m per unit time t yll and theoretical solid production m sll And to obtain the current liquid production volume m within a unit time t when the gas pressure fluctuates. ydq and current solid production m sdq This allows us to determine the amount of alcohol and ester byproducts that need to be increased or decreased. Compare the theoretical liquid production rate m yll Compared with the current liquid production rate m ydq、 Theoretical solids production m sll Compared with the current solid production m sdq This allows us to determine the amount of alcohol and ester byproducts that need to be increased or decreased. Calculate the theoretical gas production m gll Compared with the current gas production m gdq Gas production difference m gc The gas production difference m within a unit time t is calculated based on the ideal feeding ratio and stable gas production rate of the feeder. gcz The corresponding amount of material to be added needs to be adjusted.

[0032] Specifically, the gas production difference m between feeders A and B within a unit time t. gcz The calculation method for the required adjustment of the material input is as follows: When m gll +α<m gdq hour: If m ydq >m yll m sdq >m sll This indicates that both alcohol and ester byproducts have been over-feeded. In this case, the gas production difference m should be calculated based on the ideal feed ratio of the feeder and the stable gas production rate. gcz To address this, the amount of alcohol and ester byproducts fed in needs to be reduced, thereby adjusting the feeding speed of the feeder. The specific calculation method is 0.27m... eg +0.9m dmt =m gcz m eg =4m dmt , where m eg m represents the reduction in alcohol byproducts. dmt This represents the reduction in ester byproducts.

[0033] Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =52.6kg. At this time, m gll +α<mgdq If m ydq >m yll m sdq >m sll Then calculate the gas production difference m. gcz =4kg, according to the above formula for calculating the reduction of alcohol and ester by-products, the reduction of alcohol by-products m eg ≈8.08kg, reduction of ester byproducts m dmt ≈2.02kg.

[0034] If m ydq >m yll m sdq ≤m sll This indicates that too much alcohol byproduct was fed, and too little or too little ester byproduct was fed. In this case, the gas production difference m should be calculated based on the stable gas production rate. gcz To reduce the amount of alcohol byproducts fed into the feeder, the feeding speed of the feeder needs to be adjusted. The specific calculation method is 0.27m... eg =m gcz , where m eg This represents the reduction in alcohol byproducts.

[0035] Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =52.6kg. At this time, m gll +α<m gdq If m ydq >m yll m sdq ≤m sll Then calculate the gas production difference m. gcz =4kg, according to the formula for calculating the reduction of alcohol by-products mentioned above, the reduction of alcohol by-products per unit time t is m eg ≈14.81kg.

[0036] If m ydq ≤m yll m sdq ≤m sll This indicates that the amount of alcohol by-products fed is either too low or too high, or the amount of ester by-products fed is either too low or too high, or that there is a mixture of by-products that have not been fully pyrolyzed in the pyrolysis furnace. In this case, the gas production difference m should be calculated according to the ideal feeding ratio of the feeder and the stable gas production rate. gcz To address this, the amount of alcohol and ester byproducts fed in needs to be reduced, thereby adjusting the feeding speed of the feeder. The specific calculation method is 0.27m... eg +0.9m dmt =m gczm eg =4m dmt , where m eg m represents the reduction in alcohol byproducts. dmt This represents the reduction in ester byproducts.

[0037] Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =52.6kg. At this time, m gll +α<m gdq If m ydq ≤m yll m sdq ≤m sll Then calculate the gas production difference m. gcz =4kg, according to the above formula for calculating the reduction of alcohol and ester by-products, the reduction of alcohol by-products per unit time t is m eg ≈8.08kg, reduction of ester byproducts m dmt ≈2.02kg.

[0038] If m ydq ≤m yll m sdq >m sll This indicates that the amount of alcohol by-products fed is either too little or too little, while the amount of ester by-products fed is too much. In this case, the gas production difference m should be calculated according to the ideal feeding ratio of the feeder and the stable gas production rate. gcz To reduce the amount of ester byproducts fed into the feeder, the feeding speed of the feeder needs to be adjusted. The specific calculation method is 0.9m... dmt =m gcz , where m dmt This represents the reduction in ester byproducts.

[0039] Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =52.6kg. At this time, m gll +α<m gdq If m ydq ≤m yll m sdq >m sll Then calculate the gas production difference m. gcz =4kg, according to the formula for calculating the reduction of ester by-products mentioned above, the reduction of ester by-products per unit time t is m dmt ≈4.44kg.

[0040] When m gll -α>m gdq hour: If m ydq <m yll m sdq ≥m sll This indicates that the amount of alcohol by-products fed is too small, the amount of ester by-products fed is too large or too small, and there are too many impurities in the alcohol by-products. In this case, the gas production difference m should be calculated according to the ideal feeding ratio and stable gas production rate of the feeder. gcz This requires increasing the amount of alcohol byproducts fed into the feeder, thereby adjusting the feeding speed of the feeder. The specific calculation method is 0.27m. eg =m gcz , where m eg This represents the increase in alcohol byproducts; Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =44.6kg. At this time, m gll -α>m gdq If m ydq <m yll m sdq ≥m sll Then calculate the gas production difference m. gcz =4kg, according to the formula for calculating the increase of alcohol by-products mentioned above, the increase of alcohol by-products per unit time t is m eg ≈14.81kg.

[0041] If m ydq <m yll m sll <m sdq If the amount of alcohol and ester byproducts is too low, it indicates that the amount of gas produced is insufficient. In this case, calculate the gas production difference m based on the ideal feed ratio and stable gas production rate of the feeder. gcz This requires increasing the amount of alcohol and ester byproducts fed into the feeder, thereby adjusting the feeding speed of the feeder. The specific calculation method is 0.27m... eg +0.9m dmt =m gcz m eg =4m dmt , where m eg m represents the increase in alcohol byproducts. dmt This represents the increase in ester byproducts; Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll=48.6kg, actual gas production m gdq =44.6kg. At this time, m gll -α>m gdq If m ydq <m yll m sll <m sdq Then calculate the gas production difference m. gcz =4kg, according to the above formula for calculating the increase of alcohol by-products and ester by-products, the increase of alcohol by-products per unit time t is m eg ≈8.08kg, the increase in ester byproducts m dmt ≈2.02kg.

[0042] If m ydq ≥m yll m sdq ≥m sll This indicates that both alcohol and ester byproducts contain excessive impurities. In this case, the gas production difference m should be calculated according to the ideal feeding ratio and stable gas production rate of the feeder. gcz This requires increasing the amount of alcohol and ester byproducts fed into the feeder, thereby adjusting the feeding speed of the feeder. The specific calculation method is 0.27m... eg +0.9m dmt =m gcz m eg =4m dmt , where m eg m represents the increase in alcohol byproducts. dmt This represents the increase in ester byproducts; Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =44.6kg. At this time, m gll -α>m gdq If m ydq ≥m yll m sdq ≥m sll Then calculate the gas production difference m. gcz =4kg, according to the above formula for calculating the increase of alcohol by-products and ester by-products, the increase of alcohol by-products per unit time t is m eg ≈8.08kg, the increase in ester byproducts m dmt ≈2.02kg.

[0043] If m ydq ≥m yll m sdq <m sllThis indicates that the amount of alcohol byproducts fed is either too high or too low, while the amount of ester byproducts fed is too low. In this case, the gas production difference m should be calculated based on the stable gas production rate. gcz This requires increasing the amount of ester byproducts fed into the feeder, thereby adjusting the feeding speed of the feeder. The specific calculation method is as follows: 0.9m dmt =m gcz , where m dmt This represents the increase in ester byproducts.

[0044] Specifically, assuming α is 1 kg, the theoretical gas production m is obtained in a unit time t = 1 hour according to the ideal feed rate and ideal feed ratio. gll =48.6kg, actual gas production m gdq =44.6kg. At this time, m gll -α>m gdq If m ydq ≥m yll m sdq <m sll Then calculate the gas production difference m. gcz =4kg, according to the formula for calculating the increase of ester by-products, the increase of ester by-products per unit time t is m dmt ≈14.81kg.

[0045] The implementation principle of this embodiment is as follows: By monitoring the gas pressure fluctuations and gas production within the pyrolysis furnace in real time, the feeding speed of the feeder is dynamically adjusted. By controlling the feeding of different raw materials (ester byproducts, alcohol byproducts, or a combination of both), the gas production efficiency is adjusted to maintain a relatively constant level. This not only improves resource utilization and reduces waste but also prevents subsequent processes such as fuel recovery and reheating, and gas-liquid separation from being affected by unstable gas production efficiency. Simultaneously, precise control of the feeding speed ensures stable gas pressure and temperature within the pyrolysis furnace, enhancing the safety and reliability of the entire production process.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

[0047] Example 2: This embodiment provides a high-value treatment system for polyester recycling by-products, used to execute the high-value treatment method for polyester recycling by-products in Embodiment 1 above. The system includes, in sequence, a feeder, a buffer tank, a feeding sealing device, a preheating assembly, a continuous pyrolysis furnace, a pyrolysis gas purification device, a pressure stabilizing tank, a heating device, and an external storage device connected in parallel with the pressure stabilizing tank. The buffer tank is used to buffer raw materials, namely alcohol and ester by-products, which are fed into the buffer tank by the feeder. The raw materials in the buffer tank are then fed into the preheating assembly through the feeding sealing device. After preheating by the preheating assembly, the raw materials are continuously fed into the continuous pyrolysis furnace by the feeder. Pyrolysis occurs in the furnace, yielding a pyrolysis gas phase product (pyrolysis gas) and a solid product (carbon black). The pyrolysis gas phase product is condensed to separate non-condensable gases. These non-condensable gases are purified by the pyrolysis gas purification device, pressure-stabilized by the pressure stabilizing tank, and then transported to the heating device for combustion and heating. Excess non-condensable gases are stored externally for secondary use. The solid products obtained from pyrolysis are cooled to a safe temperature and then automatically briquetted and centrally processed. The system also includes, but is not limited to, auxiliary equipment such as a thermal circulation device, a solid product cooling device, a solid product conveying device, a flue gas purification device, a circulating water cooling device, and necessary electrical control equipment.

[0048] In addition, the system also includes: Initialization module: Used to set the ideal feeding ratio and ideal feeding speed of the feeder based on the gas production ratio of alcohol and ester byproducts, and to obtain the theoretical gas production m per unit time t. gll ; Gas pressure and volume acquisition module: used to acquire real-time gas pressure fluctuations within the pyrolysis furnace, and to acquire the current gas production volume m per unit time t during the gas pressure fluctuations. gdq ; Speed ​​regulation feedback module: used to compare the theoretical gas production m gll Compared with the current gas production m gdq To determine whether there is too much or too little alcohol or ester byproduct, the feeding speed of the feeder can be adjusted.

[0049] The above-mentioned air pressure and volume acquisition module includes: The real-time monitoring unit is used to acquire the real-time gas pressure fluctuation in the pyrolysis furnace under stable gas production, and to acquire the current gas pressure Pdq and the current temperature Tdq when the gas pressure fluctuates. Gas flux acquisition unit: used to acquire the gas flux Vgt at the pyrolysis gas outlet, and calculate the total gas production volume Va per unit time t based on the gas flux Vgt at the pyrolysis gas outlet. Gas production calculation unit: used to calculate the current gas production m based on the relationship between the gas production volume Va and the current gas pressure Pdq. gdq .

[0050] The implementation principle of this embodiment is as follows: The gas pressure and gas production rate within the pyrolysis furnace are monitored in real time by a gas pressure and gas volume acquisition module. Based on the fluctuations, the difference in gas production rate is calculated and fed back. The gas production rate calculation unit accurately calculates whether there is too much or too little raw material, thereby dynamically adjusting the feeding speed of the feeder. By controlling the feeding of different raw materials (ester by-products, alcohol by-products, or a combination of both), the gas production efficiency is adjusted to maintain a relatively constant efficiency. This not only improves resource utilization and reduces waste but also prevents subsequent processes such as fuel recovery and reheating, and gas-liquid separation from being affected by unstable gas production efficiency. Simultaneously, precise control of the feeding speed ensures stable gas pressure and temperature within the pyrolysis furnace, improving the safety and reliability of the entire production process. The above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for controlling the feeding of recycled polyester by-products for high-value processing, characterized in that, The method includes: The ideal feeding ratio and ideal feeding speed of the feeder are set based on the gas production ratio of alcohol by-products and ester by-products, and the theoretical gas production m per unit time t is obtained. gll ; The real-time gas pressure fluctuations inside the pyrolysis furnace are obtained, and the current gas production m within a unit time t is obtained during the gas pressure fluctuations. gdq ; Compare the theoretical gas production m gll Compared with the current gas production m gdq To determine whether there is too much or too little alcohol or ester byproduct, the feeding speed of the feeder can be adjusted accordingly. The real-time gas pressure fluctuation within the pyrolysis furnace is obtained, and the current gas production m within a unit time t is obtained during the gas pressure fluctuation. gdq include: Under stable gas production, the real-time gas pressure fluctuation in the pyrolysis furnace is obtained, and the current gas pressure Pdq and current temperature Tdq are obtained when the gas pressure fluctuates. Obtain the gas flow rate Vgt at the pyrolysis gas outlet, and calculate the total gas production volume Va per unit time t based on the gas flow rate Vgt at the pyrolysis gas outlet, i.e. Va = Vgt·t. Calculate the current gas production m based on the relationship between the total gas production volume Va and the current gas pressure Pdq. gdq ; The comparison of the theoretical gas production m gll Compared with the current gas production m gdq ,like: m gll -α≤m gdq ≤m gll If +α, then there is no need to adjust the feeding speed; m gll -α>m gdq This increases the feeding speed; m gll +α<m gdq If the feeding speed is reduced, then α is the gas production error. When the m gll -α>m gdq or the m gll +α<m gdq hour: Obtain the theoretical liquid production rate m per unit time t yll and theoretical solid production m sll And to obtain the current liquid production volume m within a unit time t during the pressure fluctuation. ydq and current solid production m sdq ; Compare the theoretical liquid production rate m yll Compared with the current liquid production rate m ydq、 The theoretical solids yield m sll Compared with the current solid production m sdq ; Calculate the theoretical gas production m gll Compared with the current gas production m gdq Gas production difference m gc Based on the ideal feeding ratio and stable gas production rate of the feeder, the gas production difference m within a unit time t is calculated. gcz The corresponding amount of material to be adjusted; When the m gll +α<m gdq hour: If m ydq >m yll m sdq >m sll This reduces the amount of alcohol and ester byproducts fed into the feeder, thereby reducing the feeding speed of the feeder for alcohol and ester byproducts. If m ydq >m yll m sdq ≤m sll This reduces the amount of alcohol by-products fed into the machine, thereby reducing the feeding speed of the alcohol by-product feeder. If m ydq ≤m yll m sdq ≤m sll This reduces the amount of alcohol and ester byproducts fed into the machine, thereby reducing the feeding speed of the alcohol and ester byproduct feeder. If m ydq ≤m yll m sdq >m sll This reduces the amount of ester by-products fed into the machine, thereby reducing the feeding speed of the ester by-product feeder.

2. The method according to claim 1, characterized in that, The current gas production volume m is calculated based on the relationship between the total gas production volume Va and the current gas pressure Pdq. gdq The calculation formula is as follows: Based on PV=nRT and n=m / M, we can obtain... m gdq =Pdq·VM / RT=Pdq·(10^-3)Va·M / R(Tdq+273.15); In the formula, P is the pressure, V is the gas volume in L, R is the ideal gas constant, T is the temperature in K, and M is the molar mass of the gas.

3. The method according to claim 1, characterized in that, The ideal feeding ratio is 8 parts alcohol by-product to 2 parts ester by-product, that is, 8 parts alcohol by-product and 2 parts ester by-product.

4. The method according to claim 3, characterized in that, The stable gas production rate of the alcohol by-products is 27%, the stable liquid production rate is 63%, and no solids are produced; the stable gas production rate of the ester by-products is 90%, the stable solid production rate is 10%, and no liquids are produced.

5. The method according to claim 4, characterized in that, When the m gll -α>m gdq hour: If m ydq <m yll m sdq ≥m sll This increases the amount of alcohol by-products fed into the machine, thereby increasing the feeding speed of the alcohol by-product feeder. If m ydq <m yll m sdq <m sll This increases the amount of alcohol and ester by-products fed into the machine, thereby increasing the feeding speed of the alcohol and ester by-product feeder. If m ydq ≥m yll m sdq ≥m sll This increases the amount of alcohol and ester by-products fed into the machine, thereby increasing the feeding speed of the alcohol and ester by-product feeder. If m ydq ≥m yll m sdq <m sll This increases the amount of ester by-products fed, thereby increasing the feeding speed of the ester by-product feeder.

6. A system for high-value processing of polyester recycling by-products for performing the method according to any one of claims 1-5, characterized in that, The system includes: Initialization module: Used to set the ideal feeding ratio and ideal feeding speed of the feeder based on the gas production ratio of alcohol and ester byproducts, and to obtain the theoretical gas production m per unit time t. gll ; Gas pressure and volume acquisition module: used to acquire real-time gas pressure fluctuations within the pyrolysis furnace, and to acquire the current gas production volume m per unit time t during the gas pressure fluctuations. gdq ; Speed ​​regulation feedback module: used to compare the theoretical gas production m gll Compared with the current gas production m gdq To determine whether there is too much or too little alcohol or ester byproduct, the feeding speed of the feeder can be adjusted.

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